This is Damai's first litter of cubs, fathered by the Zoo's 12-year-old male tiger, Kavi.

"It's taken more than two years of perseverance getting to know Damai and Kavi and letting them get to know each other so that we could reach this celebratory moment," said zoo biologist Craig Saffoe. "All I can do is smile because the team has realized our goal of producing critically endangered tiger cubs. Damai came to us as a young tiger herself, so it's really special to see her become a great mom."

Damai underwent an ultrasound back in June after she started gaining weight and exhibiting behaviors indicative of pregnancy.

On Tuesday, Damai left the cubs for the first time, which officials say is a good sign that she is comfortable.

The public won't be introduced to the cubs anytime soon. Zoo keepers want to give Damai time to bond with her babies. The new family will be watched remotely and will not be put on exhibit for several months. The cubs must first undergo a series of health exams and received all the necessary vaccinations. Keepers also want to make sure they're acclimated to the exhibit before the cubs are released into the yards.

Sumatran tigers are a critically endangered species. It is estimated that between 400 and
500 exist in the wild. There are 65 Sumatran tigers living in accredited
zoos in North America in addition to these cubs.